Centroid of a set of N-dimensional points: Difference between revisions
Centroid of a set of N-dimensional points (view source)
Revision as of 19:59, 21 July 2023
, 10 months agoAdded Algol 68
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(Added Algol 68) |
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;; [[https://mathworld.wolfram.com/GeometricCentroid.html Wolfram Mathworld on Centroid]]
=={{header|ALGOL 68}}==
<syntaxhighlight lang="algol68">
BEGIN # find the centroid of some N-dimensional points #
# returns the centroid of points #
OP CENTROID = ( [,]REAL points )[]REAL:
BEGIN
INT number of points = ( 1 UPB points - 1 LWB points ) + 1;
[ 2 LWB points : 2 UPB points ]REAL result;
FOR j FROM 2 LWB points TO 2 UPB points DO
REAL sum := 0;
FOR i FROM 1 LWB points TO 1 UPB points DO sum +:= points[ i, j ] OD;
result[ j ] := sum / number of points
OD;
result
END # CENTROID # ;
OP A = ( INT v )[]REAL: v; # coerces v to []REAL #
OP FMT = ( REAL v )STRING: # formsts v with up to 2 decimals #
BEGIN
STRING result := fixed( v, -0, 2 );
IF result[ LWB result ] = "." THEN "0" +=: result FI;
WHILE result[ UPB result ] = "0" DO result := result[ : UPB result - 1 ] OD;
IF result[ UPB result ] = "." THEN result := result[ : UPB result - 1 ] FI;
" " + result
END # FMT # ;
OP SHOW = ( []REAL v )VOID: # show a 1D array (row) of reals #
BEGIN
print( ( "[" ) );
FOR i FROM LWB v TO UPB v DO print( ( FMT v[ i ] ) ) OD;
print( ( " ]" ) )
END # SHOW # ;
OP SHOW = ( [,]REAL v )VOID: # show a 2D array of reals #
BEGIN
print( ( "[" ) );
FOR i FROM 1 LWB v TO 1 UPB v DO SHOW v[ i, : ] OD;
print( ( "]" ) )
END # SHOW # ;
# task test cases #
PROC test = ( [,]REAL points )VOID: # test the CENTROID operator #
BEGIN SHOW points; print( ( " -> " ) );
SHOW CENTROID points; print( ( newline ) )
END # test # ;
test( ( A(1), A(2), A(3) ) );
test( ( ( 8, 2 ), ( 0, 0 ) ) );
test( ( ( 5, 5, 0 ), ( 10, 10, 0 ) ) );
test( ( ( 1, 3.1, 6.5 ), ( -2, -5, 3.4 )
, ( -7, -4, 9 ), ( 2, 0, 3 )
)
);
test( ( ( 0, 0, 0, 0, 1 ), ( 0, 0, 0, 1, 0 )
, ( 0, 0, 1, 0, 0 ), ( 0, 1, 0, 0, 0 )
)
)
END
</syntaxhighlight>
{{out}}
<pre>
[[ 1 ][ 2 ][ 3 ]] -> [ 2 ]
[[ 8 2 ][ 0 0 ]] -> [ 4 1 ]
[[ 5 5 0 ][ 10 10 0 ]] -> [ 7.5 7.5 0 ]
[[ 1 3.1 6.5 ][ -2 -5 3.4 ][ -7 -4 9 ][ 2 0 3 ]] -> [ -1.5 -1.47 5.47 ]
[[ 0 0 0 0 1 ][ 0 0 0 1 0 ][ 0 0 1 0 0 ][ 0 1 0 0 0 ]] -> [ 0 0.25 0.25 0.25 0.25 ]
</pre>
=={{header|C}}==
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